"Entering The Death Meadow"

Ainsley was willing to risk her life for the Godfather and the Godfather was also the same. 

Because of this, their bond was stronger than other shamans and their contracted spirits. 

The strong bond resulted in the smoother operation when the Godfather possessed Ainsley. 

The speed of possession was so fast because Ainsley didn't reject the Godfather and believed that when he controlled her body, he wouldn't harm her. 

At the same time, the Godfather also wanted Ainsley to be independent so that she could use his ability without him possessing her body. 

A lot of spirits didn't want this because once the shamans could do this, their existence would be reduced even further. 

They would only be weapons for fighting and many shamans contracted a lot of spirits just to borrow their abilities. 

The spirits became an 'ability bank'.